Automatic spray equipment is well known in the prior art. There are, for example, the devices illustrated and described in U.S. Pat. Nos. 4,744,518; 4,915,303; 5,044,564; 5,279,461; 5,322,221; 5,344,078; and 5,456,414, and the references cited therein. The disclosures of these references are hereby incorporated herein by reference. No representation is intended by this listing that this is a complete listing of all pertinent prior art, or that a thorough search of all pertinent prior art has been conducted, or that no better prior art exists. Nor should any such representation be inferred.
Many automatic spray dispensers are pneumatic dispensers. That is, compressed gases or mixtures of gases, typically compressed air, are used in the atomization and dispensing of the materials they spray. Typically, jets of air are directed onto two opposite sides of a jet of the material to be atomized and dispensed, assisting in the atomization of the material and shaping the atomized material into somewhat of a fan shape, fanning out from the orifice of the nozzle through which the material is dispensed. The portion of a dispenser which directs the opposed air jets onto the stream of material being dispensed through the nozzle is generally referred to as an air cap. Such an air cap typically includes a pair of projections, sometimes called horns, which contain passageways and orifices through which the shaping air is directed onto the stream of material. The streams of air flowing onto the two opposite surfaces of the stream of material flatten it into a somewhat elliptical cross-section, fan shaped pattern. In automatic coating dispensing equipment, generally, equipment which is not manipulated by a human operator, the dispenser is usually set up so that the long dimension of the cross section of the fan shaped pattern is oriented either horizontally (sometimes hereinafter referred to as a horizontal fan spray) or vertically (sometimes hereinafter referred to as a vertical fan spray), depending upon the requirements and/or preferences of a particular application. In the past, this has meant using sometimes cumbersome devices and methods to establish that the air cap is properly oriented to produce a horizontal fan spray or a vertical fan spray.